[Discussion] can we stop arguing about water content until somebody posts a number
Trying to get a straight answer on this: can we stop arguing about water content until somebody posts a number. The document I was worried about turned out to be a re-issue with a later creation date. Asked, got the original, entirely ordinary. Sent one vial to Medutest and Janoshik. 99.3% and a claimed 98.5%. Cost…
Area percent or net peptide content? They answer different questions.
Did you get the chromatogram or only the summary line?
area% is not mass%, and the difference is the whole game
Correcting myself upthread: I said the date was missing and it is on the second page, which I had not scrolled to.
Not quite. Two labs with different gradients can resolve a close-eluting impurity differently and both be reporting honestly.
a total of 0.4% tells you less than four named impurities adding to 0.6%
chromatogram or it did not happen
the related substances line is where the story is
Same view. Homopeptide prints the column and the gradient, which means somebody could actually reproduce the run.